Electronic component-mounted structure, IC card and COF package

Abstract

Disclosed is an electronic component-mounted structure including: a substrate, a conductive wiring pattern formed on a surface of the substrate, and an electronic component having an external terminal and being placed on the surface of the substrate at a mounting position including a terminal joint position of the conductive wiring pattern. The external terminal is joined to the conductive wiring pattern at the terminal joint position such that the external terminal is embedded in the conductive wiring pattern. Therefore, the junction between the external terminal and the conductive wiring pattern can have a high strength as compared with that obtained by joining the external terminal of the electronic component to the conductive wiring pattern merely on the surface of the conductive wiring pattern.

The invention claimed is: 
     
       1. An electronic component-mounted structure comprising:
 a substrate, 
 a conductive wiring pattern formed on a surface of the substrate, and 
 an electronic component having an external terminal and being placed on the surface of the substrate at a mounting position including a terminal joint position of the conductive wiring pattern, 
 the external terminal being joined to the conductive wiring pattern at the terminal joint position, the external terminal being embedded in the conductive wiring pattern, 
 the conductive wiring pattern being formed by curing a photocurable wiring-forming material that has fluidity or deformability and includes a solvent, a dispersant, and metal nanoparticles coated with the dispersant in the solvent, 
 the substrate having light permeability, and 
 the metal nanoparticles being in direct contact and join with each other. 
 
     
     
       2. The electronic component-mounted structure according to  claim 1 , wherein the wiring-forming material contains Cu particles having an average particle diameter of 1 to 10 nm. 
     
     
       3. The electronic component-mounted structure according to  claim 1 , wherein the external terminal of the electronic component contains Cu in at least an outermost surface of the external terminal. 
     
     
       4. The electronic component-mounted structure according to  claim 1 , wherein the substrate is a film substrate. 
     
     
       5. An IC card comprising:
 a substrate, 
 an antenna circuit formed on a surface of the substrate, and 
 a bare chip component having an external terminal and being placed on the surface of the substrate at a mounting position including a terminal joint position of the antenna circuit, 
 the external terminal being joined to the antenna circuit at the terminal joint position, and the external terminal being embedded in the antenna circuit, 
 the antenna circuit being formed by curing a photocurable wiring-forming material that has fluidity or deformability and includes a solvent, a dispersant, and metal nanoparticles coated with the dispersant in the solvent, 
 the substrate having light permeability, and 
 the metal nanoparticles being in direct contact and join with each other. 
 
     
     
       6. The IC card according to  claim 5 , wherein the wiring-forming material includes Cu particles having an average particle diameter of 1 to 10 nm. 
     
     
       7. The IC card according to  claim 5 , wherein the substrate includes at least one selected from polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polybutylene terephthalate, polyphenyl sulfide, polyether ether ketone, polycarbonate, liquid crystal polymer, polystyrene, acrylic resin, polyacetal, polyphenyl ether, acrylonitrile-styrene copolymer, and acrylonitrile-butadiene-styrene copolymer resin. 
     
     
       8. The IC card according to  claim 5 , wherein the substrate is a film substrate. 
     
     
       9. A COF package comprising:
 a film substrate, 
 a conductive wiring pattern formed on a surface of the substrate, 
 a first electronic component having an external terminal and being placed on the surface of the substrate at a mounting position including a terminal joint position of the conductive wiring pattern, and 
 a second electronic component connected to the first electronic component via the conductive wiring pattern, 
 the external terminal of the first electronic component being joined to the conductive wiring pattern at the terminal joint position, the external terminal being embedded in the conductive wiring pattern, 
 the conductive wiring pattern being formed by curing a photocurable wiring-forming material that has fluidity or deformability and includes a solvent, a dispersant, and metal nanoparticles coated with the dispersant in the solvent, 
 the substrate having light permeability, and 
 the metal nanoparticles being in direct contact and join with each other. 
 
     
     
       10. The COF package according to  claim 9 , wherein the wiring-forming material includes Cu particles having an average particle diameter of 1 to 10 nm. 
     
     
       11. The COF package according to  claim 9 , wherein the substrate includes at least one selected from polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polybutylene terephthalate, polyphenyl sulfide, polyether ether ketone, polycarbonate, liquid crystal polymer, polystyrene, acrylic resin, polyacetal, polyphenyl ether, acrylonitrile-styrene copolymer, and acrylonitrile-butadiene-styrene copolymer resin. 
     
     
       12. The electronic component-mounted structure according to  claim 1 , wherein the wiring-forming material is cured by irradiating light through the substrate onto the wiring-forming material, with the external terminal being sunk in the wiring-forming material at the terminal joint position, thereby to remove the dispersant from the metal nanoparticles, so that the metal nanoparticles come into direct contact and join with each other. 
     
     
       13. The IC card according to  claim 5 , wherein the wiring-forming material is cured by irradiating light through the substrate onto the wiring-forming material, with the external terminal being sunk in the wiring-forming material at the terminal joint position, thereby to remove the dispersant from the metal nanoparticles, so that the metal nanoparticles come into direct contact and join with each other. 
     
     
       14. The COF package according to  claim 9 , wherein the wiring-forming material is cured by irradiating light through the substrate onto the wiring-forming material, with the external terminal being sunk in the wiring-forming material at the terminal joint position, thereby to remove the dispersant from the metal nanoparticles, so that the metal nanoparticles come into direct contact and join with each other.